build: drop Python 3.6 supportnedbat/drop-36

14 files changed, 31 insertions, 28 deletions

diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 9385ff5f..df9ce118 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -32,8 +32,7 @@ jobs:
           - windows-latest
         python-version:
           # When changing this list, be sure to check the [gh-actions] list in
-          # tox.ini so that tox will run properly.
-          - "3.6"
+          # tox.ini so that tox will run properly. PYVERSIONS
           - "3.7"
           - "3.8"
           - "3.9"
diff --git a/.github/workflows/kit.yml b/.github/workflows/kit.yml
index 9bc8e192..af3a6bea 100644
--- a/.github/workflows/kit.yml
+++ b/.github/workflows/kit.yml
@@ -56,7 +56,7 @@ jobs:
           #       "macos": ["arm64", "x86_64"],
           #       "windows": ["x86", "AMD64"],
           #   }
-          #   pys = ["cp36", "cp37", "cp38", "cp39", "cp310"]
+          #   pys = ["cp37", "cp38", "cp39", "cp310"]   # PYVERSIONS
           #   os_arch_pys = {
           #     ("macos", "arm64"): ["cp38", "cp39", "cp310"],
           #   }
@@ -74,17 +74,14 @@ jobs:
           #               }
           #               print(f"- {json.dumps(them)}")
           # ]]]
-          - {"os": "ubuntu", "py": "cp36", "arch": "x86_64"}
           - {"os": "ubuntu", "py": "cp37", "arch": "x86_64"}
           - {"os": "ubuntu", "py": "cp38", "arch": "x86_64"}
           - {"os": "ubuntu", "py": "cp39", "arch": "x86_64"}
           - {"os": "ubuntu", "py": "cp310", "arch": "x86_64"}
-          - {"os": "ubuntu", "py": "cp36", "arch": "i686"}
           - {"os": "ubuntu", "py": "cp37", "arch": "i686"}
           - {"os": "ubuntu", "py": "cp38", "arch": "i686"}
           - {"os": "ubuntu", "py": "cp39", "arch": "i686"}
           - {"os": "ubuntu", "py": "cp310", "arch": "i686"}
-          - {"os": "ubuntu", "py": "cp36", "arch": "aarch64"}
           - {"os": "ubuntu", "py": "cp37", "arch": "aarch64"}
           - {"os": "ubuntu", "py": "cp38", "arch": "aarch64"}
           - {"os": "ubuntu", "py": "cp39", "arch": "aarch64"}
@@ -92,22 +89,19 @@ jobs:
           - {"os": "macos", "py": "cp38", "arch": "arm64"}
           - {"os": "macos", "py": "cp39", "arch": "arm64"}
           - {"os": "macos", "py": "cp310", "arch": "arm64"}
-          - {"os": "macos", "py": "cp36", "arch": "x86_64"}
           - {"os": "macos", "py": "cp37", "arch": "x86_64"}
           - {"os": "macos", "py": "cp38", "arch": "x86_64"}
           - {"os": "macos", "py": "cp39", "arch": "x86_64"}
           - {"os": "macos", "py": "cp310", "arch": "x86_64"}
-          - {"os": "windows", "py": "cp36", "arch": "x86"}
           - {"os": "windows", "py": "cp37", "arch": "x86"}
           - {"os": "windows", "py": "cp38", "arch": "x86"}
           - {"os": "windows", "py": "cp39", "arch": "x86"}
           - {"os": "windows", "py": "cp310", "arch": "x86"}
-          - {"os": "windows", "py": "cp36", "arch": "AMD64"}
           - {"os": "windows", "py": "cp37", "arch": "AMD64"}
           - {"os": "windows", "py": "cp38", "arch": "AMD64"}
           - {"os": "windows", "py": "cp39", "arch": "AMD64"}
           - {"os": "windows", "py": "cp310", "arch": "AMD64"}
-        # [[[end]]] (checksum: dd4b4a059d9e8b8ae7e389a428a999f9)
+        # [[[end]]] (checksum: 4b02126e18e2b3798783d3cc6f303552)
       fail-fast: false
 
     steps:
diff --git a/.github/workflows/quality.yml b/.github/workflows/quality.yml
index 2eb64b59..6da0627e 100644
--- a/.github/workflows/quality.yml
+++ b/.github/workflows/quality.yml
@@ -33,7 +33,7 @@ jobs:
       - name: "Install Python"
         uses: "actions/setup-python@v2"
         with:
-          python-version: "3.8"
+          python-version: "3.7" # Minimum of PYVERSIONS
           cache: pip
           cache-dependency-path: 'requirements/*.pip'
 
@@ -59,7 +59,7 @@ jobs:
       - name: "Install Python"
         uses: "actions/setup-python@v2"
         with:
-          python-version: "3.8"
+          python-version: "3.7" # Minimum of PYVERSIONS
           cache: pip
           cache-dependency-path: 'requirements/*.pip'
 
diff --git a/.github/workflows/testsuite.yml b/.github/workflows/testsuite.yml
index 1fd6df4c..54859b25 100644
--- a/.github/workflows/testsuite.yml
+++ b/.github/workflows/testsuite.yml
@@ -32,8 +32,7 @@ jobs:
           - windows-latest
         python-version:
           # When changing this list, be sure to check the [gh-actions] list in
-          # tox.ini so that tox will run properly.
-          - "3.6"
+          # tox.ini so that tox will run properly. PYVERSIONS
           - "3.7"
           - "3.8"
           - "3.9"
diff --git a/CHANGES.rst b/CHANGES.rst
index 86612877..8ac4997b 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -22,6 +22,8 @@ This list is detailed and covers changes in each pre-release version.
 Unreleased
 ----------
 
+- Dropped support for Python 3.6, which ended support on 2021-12-23.
+
 - Releases now have MacOS arm64 wheels for Apple Silicon (fixes `issue 1288`_).
 
 .. _issue 1288: https://github.com/nedbat/coveragepy/issues/1288
diff --git a/README.rst b/README.rst
index aaa05425..5aee2863 100644
--- a/README.rst
+++ b/README.rst
@@ -19,7 +19,9 @@ library to determine which lines are executable, and which have been executed.
 
 Coverage.py runs on these versions of Python:
 
-* CPython 3.6 through 3.11.
+.. PYVERSIONS
+
+* CPython 3.7 through 3.11.
 * PyPy3 7.3.7.
 
 Documentation is on `Read the Docs`_.  Code repository and issue tracker are on
@@ -29,8 +31,8 @@ Documentation is on `Read the Docs`_.  Code repository and issue tracker are on
 .. _GitHub: https://github.com/nedbat/coveragepy
 
 
-**New in 6.x:** dropped support for Python 2.7 and 3.5; added support for 3.10
-match/case statements.
+**New in 6.x:** dropped support for Python 2.7, 3.5, and 3.6;
+added support for 3.10 match/case statements.
 
 
 For Enterprise
diff --git a/ci/download_gha_artifacts.py b/ci/download_gha_artifacts.py
index 7828d3f8..df22c688 100644
--- a/ci/download_gha_artifacts.py
+++ b/ci/download_gha_artifacts.py
@@ -21,7 +21,7 @@ def download_url(url, filename):
             for chunk in response.iter_content(16*1024):
                 f.write(chunk)
     else:
-        raise Exception(f"Fetching {url} produced: {response.status_code=}")
+        raise Exception(f"Fetching {url} produced: status={response.status_code}")
 
 def unpack_zipfile(filename):
     """Unpack a zipfile, using the names in the zip."""
diff --git a/coverage/version.py b/coverage/version.py
index 96dbd71f..8752e843 100644
--- a/coverage/version.py
+++ b/coverage/version.py
@@ -5,7 +5,7 @@
 # This file is exec'ed in setup.py, don't import anything!
 
 # Same semantics as sys.version_info.
-version_info = (6, 2, 1, "alpha", 0)
+version_info = (6, 3, 0, "alpha", 0)
 
 
 def _make_version(major, minor, micro, releaselevel, serial):
diff --git a/doc/contributing.rst b/doc/contributing.rst
index 1ccb4061..653e2a69 100644
--- a/doc/contributing.rst
+++ b/doc/contributing.rst
@@ -37,7 +37,9 @@ The coverage.py code is hosted on a GitHub repository at
 https://github.com/nedbat/coveragepy.  To get a working environment, follow
 these steps:
 
-#.  (Optional, but recommended) Create a Python 3.8 virtualenv to work in,
+.. minimum of PYVERSIONS:
+
+#.  (Optional, but recommended) Create a Python 3.7 virtualenv to work in,
     and activate it.
 
 #.  Clone the repository::
diff --git a/doc/index.rst b/doc/index.rst
index 3c29f51d..9661797b 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -16,7 +16,9 @@ not.
 The latest version is coverage.py |release|, released |release_date|.  It is
 supported on:
 
-* Python versions 3.6 through 3.11.
+.. PYVERSIONS
+
+* Python versions 3.7 through 3.11.
 
 * PyPy3 7.3.7.
 
diff --git a/howto.txt b/howto.txt
index a3784352..b11f3481 100644
--- a/howto.txt
+++ b/howto.txt
@@ -6,7 +6,8 @@
         version_info = (4, 0, 2, "beta", 1)
         version_info = (4, 0, 2, "candidate", 1)
         version_info = (4, 0, 2, "final", 0)
-- Python version number in classifiers in setup.py
+- Supported Python version numbers. Search for "PYVERSIONS".
+    - Python version number in classifiers in setup.py
 - Copyright date in NOTICE.txt
 - Update CHANGES.rst, including release date.
     - don't forget the jump target
diff --git a/setup.cfg b/setup.cfg
index 221e1230..e13f4835 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -12,6 +12,7 @@ filterwarnings =
     ignore:dns.hash module will be removed:DeprecationWarning
     ignore:Using or importing the ABCs:DeprecationWarning
     ignore:the imp module is deprecated in favour of importlib:DeprecationWarning
+    ignore:distutils Version classes are deprecated:DeprecationWarning
 
 # xfail tests that pass should fail the test suite
 xfail_strict = true
diff --git a/setup.py b/setup.py
index efea78b8..00f6086d 100644
--- a/setup.py
+++ b/setup.py
@@ -32,6 +32,7 @@ if bool(int(os.getenv("COVERAGE_QUIETER", "0"))):
 # Get or massage our metadata.  We exec coverage/version.py so we can avoid
 # importing the product code into setup.py.
 
+# PYVERSIONS
 classifiers = """\
 Environment :: Console
 Intended Audience :: Developers
@@ -39,7 +40,6 @@ License :: OSI Approved :: Apache Software License
 Operating System :: OS Independent
 Programming Language :: Python
 Programming Language :: Python :: 3
-Programming Language :: Python :: 3.6
 Programming Language :: Python :: 3.7
 Programming Language :: Python :: 3.8
 Programming Language :: Python :: 3.9
@@ -77,7 +77,7 @@ elif version_info[3] in ['beta', 'candidate']:
 else:
     assert version_info[3] == 'final'
     devstat = "5 - Production/Stable"
-classifier_list.append("Development Status :: " + devstat)
+classifier_list.append(f"Development Status :: {devstat}")
 
 # Create the keyword arguments for setup()
 
@@ -132,7 +132,7 @@ setup_args = dict(
         'Issues': 'https://github.com/nedbat/coveragepy/issues',
         'Twitter': 'https://twitter.com/coveragepy',
     },
-    python_requires=">=3.6",
+    python_requires=">=3.7",    # minimum of PYVERSIONS
 )
 
 # A replacement for the build_ext command which raises a single exception
diff --git a/tox.ini b/tox.ini
index 6ac0bb9e..1164b05c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,7 +3,8 @@
 
 [tox]
 # When changing this list, be sure to check the [gh-actions] list below.
-envlist = py{36,37,38,39,310,311}, pypy3, doc, lint
+# PYVERSIONS
+envlist = py{37,38,39,310,311}, pypy3, doc, lint
 skip_missing_interpreters = {env:COVERAGE_SKIP_MISSING_INTERPRETERS:True}
 toxworkdir = {env:TOXWORKDIR:.tox}
 
@@ -15,7 +16,7 @@ extras =
 deps =
     -r requirements/pip.pip
     -r requirements/pytest.pip
-    py{36,37,38,39,310}: -r requirements/light-threads.pip
+    py{37,38,39,310}: -r requirements/light-threads.pip
 
 # Windows can't update the pip version with pip running, so use Python
 # to install things.
@@ -90,8 +91,8 @@ commands =
     check-manifest --ignore 'lab/*,perf/*,doc/sample_html/*,.treerc,.github*'
 
 [gh-actions]
+# PYVERSIONS
 python =
-    3.6: py36
     3.7: py37
     3.8: py38
     3.9: py39